In August 2007, aged just 8 months my little boy William was diagnosed with a massive irreparable hole in his heart requiring urgent open-heart surgery.

He was immediately referred to Great Ormond Street Children's Hospital where on 31st August 2007 specialist surgeons operated on him to save his life.

Handing your child over for such a major operation is extremely scary stuff, knowing there's a chance, albeit a slim one that you might never see them alive again.

Thankfully, Great Ormond Street's reputation as being just about the best in the world is with very good reason - the operation went well, William made a text-book recovery and is growing up to be a brilliant, perfectly normal, healthy little boy.

To put his story into context, although William's was an extremely serious operation involving full heart and lung bypass, in the Cardio Critical Intensive Care unit his was by far the most straightforward case. Imagine being three or four years old and on your second or third heart transplant or on an artificial heart machine for months on end because yours has stopped working.

I left Great Ormond Street in awe of the immense skill and genuine care that I'd witnessed and told myself that one day I'd do something for them in return...

I'm an OK runner - I do half-marathons in around 1hr 40 or so, but at no point after finishing one have I ever thought that I'd like to do another one back to back. Still, I've been saving this moment for something suitably difficult.

That's why, with my good friend Adam Macaulay who's very kindly also raising money with me, I'm proud to be running The 2009 Flora London Marathon for GOSH.

These people do amazing, pioneering work every day, treating children with the most complicated, life-threatening illnesses -  it also seems fitting that this year they're raising money for a new cardiac wing, so please sponsor me.

Thanks for your support...but more importantly your hard-earned cash.

JC

Donating through Justgiving is quick, easy and totally secure. It’s also the most efficient way to sponsor me: Great Ormond Street Hospital Children's Charity (GOSHCC) gets your money faster and, if you’re a UK taxpayer, Justgiving makes sure 25% in Gift Aid, plus a 3% supplement, are added to your donation.

Moderately interesting training milestones:

Jan 09: 9 miles - 65 mins

Feb 09: 10 miles: 75 mins

1 Mar 09: Roding Valley half marathon: 1hr 42 mins

22 Mar 09: 20 miles off-road: 3hrs

5th Apr: Nike London 20 miler: 2hrs 47 mins

26th April: Flora London Marathon: I ran it in 4hrs 30 - job done.